Characterization of transparent conductive thin films of indium oxide

A metal alloy target of indium doped with about 5% by weight tin was rf sputtered in 100% oxygen onto quartz substrates. These films of indium−tin oxide were then annealed at temperatures up to 600°C in an argon−flow system. Their optical and electrical properties were examined as a function of annealing temperature. Optimum film properties include a sheet resistance of 2−3 Ω/⧠ with a transparency of 95% over the entire visible region. Optical extinction coefficients, percent transmission, and refractive indices were determined as a function of annealing temperature and sheet resistance. Results show that the infrared reflection loss of films of indium−tin oxide can be attributed to the amount of oxygen vacancies which are incorporated into the film.